1. Field of the Invention
The present invention relates to an apparatus and method for controlling cooling of a gantry having a linear motor, and more particularly to an apparatus and method for controlling cooling of a gantry in which peripheral environment of a linear motor of a gantry is measured, and if a gantry is overheated, it is cooled by using a cooling fan or an air nozzle.
2. Description of the Background Art
Generally, a surface mounting device (SMD) is to mount electronic components on a printed circuit board (PCB), for which an X-Y gantry including a pickup module is employed and a linear motor is adopted to the X-Y gantry as a driving force.
FIG. 1 is a schematic perspective view of a gantry having a linear motor in accordance with a conventional art.
As shown in the drawing, the conventional gantry includes a plurality of linear motors 10 adopted to a Y-axis frame and a linear motor 20 adopted to an X-axis frame.
Each linear motor 10 adopted to the Y-axis frame includes a stator 11 and a mover 12. The stator 11 includes a xe2x80x98Uxe2x80x99-type frame 11a and a plurality of permanent magnets 11b arranged at predetermined intervals at the inner both side surfaces of the xe2x80x98Uxe2x80x99-type frame 11a. The mover 12 includes a flat-type frame 12a and a coil block 12b formed at the bottom surface of the flat-type frame 12a. The coil block 12b is formed in a manner that a plurality of coils (not shown) are arranged at predetermined intervals at the bottom surface of the flat type frame 12a and molded by an insulating material.
The linear motor 20 adopted to the X-axis frame installed on the mover 12 of the linear motors 10 of the Y-axis frame also includes a stator 21 and a mover 22, similarly to the linear motors 10 of the Y-axis frame.
The stator 21 includes a xe2x80x98Uxe2x80x99-type frame 21a and a plurality of permanent magnets 21b, and the mover 22 includes a flat-type frame 22a and a coil block 22b with a plurality of coils (not shown) arranged.
With the X-Y gantry constructed as described above, a pickup module (not shown) for pick and place components is installed at a predetermined portion of the mover 22 of the linear motor 20 adopted to the X-axis frame. Movement of the pickup module in the X-axis direction is made by the mover 22 of the X-axis linear motor 20, while movement of the pickup module in the Y-axis direction is made by the mover 12 of the plurality of linear motors 10 of the Y-axis frame.
In order for the pickup module to pick up and place electronic components on a printed circuit board (not shown), the upper portion of the printed circuit board is moved in the X-Y direction by the mover 12 of the Y-axis linear motor 110 and the mover 22 of the X-axis linear motor 20.
In order to move the pickup module in a predetermined direction, the Y-axis linear motor 10 and the X-axis linear motor 20 are used for a long time. In this case, heat is generated from the coil blocks 12b and 22b formed at each stators 12 and 22. That is, the coil blocks 12b and 22b formed at the stators 12 and 22 includes the plurality of coils, so that when a driving power source is continuously supplied to the plurality of coils, heat is inevitably generated.
Conventionally, however, there is no method for removing the heat generated from the Y-axis linear motors 10 and the X-axis linear motor 20, so that the linear motor is overloaded, causing that the gantry is stopped or malfunctioned.
Therefore, an object of the present invention is to provide an apparatus and method for controlling cooling of a gantry having a linear motor which is capable of controlling a velocity of an Y-axis linear motor and an X-axis linear motor to lower down heat of a linear motor when the linear motor of a gantry is overheated.
Another object of the present invention is to provide an apparatus and method for controlling cooling of a gantry having a linear motor which is capable of cooling an overheated linear motor by driving a cooling unit when the linear motor of a gantry is overheated.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided an apparatus for controlling cooling of a gantry having a linear motor including: a stator provided with a first temperature sensor, having a heat sink and a cooling fan at predetermined portions of an X-axis and an Y-axis linear motors; a mover provided with a second temperature sensor, having a heat sink installed on the upper surface of an X-axis and a Y-axis linear motors; an encoder for sensing a position and velocity of the mover; an encoder periphery sensor part for measuring surroundings (a temperature, a humidity and a pressure) of the encoder; an A/D converter for receiving a first and a second temperature signals and converting them from an analog signal to a digital signal and outputting the same; a controller for controlling a drive signal outputted from a mover driver unit to control the velocity of the Y-axis linear motor and the X-axis linear motor; a D/V converter for converting digital signals, that is, a cooling fan control signal and an air valve control signal to a plurality of drive signals, that is, analog signals; and a mover driver for providing the drive signal to a coil block.
To achieve to above objects, there is also provided a method for controlling cooling of a gantry including the steps of: operating at least one mover (S11); measuring temperatures of an X-axis and a Y-axis stators (Txs, Tys) by means of temperature sensors (S12); measuring temperatures of an X-axis and a Y-axis movers (Txm, Tym) by means of temperature sensors (S13); storing the measured temperature (Txs, Tys, Txm and Tym) on the stators and movers and comparing them with a pre-set temperature, that is, a comparative value (S14); storing the temperature information (Txs, Tys, Txm and Tym), comparing them with the comparative value of the pre-set temperature, and computing a difference between them in case that the temperatures (Txs, Tys, Txm and Tym) are greater than the pre-set comparative value (S15); computing a temperature gain corresponding to the computed temperature difference (S16); and driving a first and a second cooling fans 14a and 14b and an air valve 33 as long as the temperature gain, to perform cooling (S17).
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.